This gene encodes the D3 subtype of the dopamine receptor. The D3 subtype inhibits adenylyl cyclase through inhibitory G-proteins. This receptor is expressed in phylogenetically older regions of the brain, suggesting that this receptor plays a role in cognitive and emotional functions. It is a target for drugs which treat schizophrenia, drug addiction, and Parkinson's disease.[3] Alternative splicing of this gene results in multiple transcript variants that would encode different isoforms, although some variants may be subject to nonsense-mediated decay (NMD).[2]